1. Field of the Invention
The instant invention relates to a motor fuel composition containing a reaction product and a polyolefin polymer/copolymer, and to a concentrate containing said reaction product and polymer/copolymer employed as a motor fuel additive. More particularly, the instant invention relates to a motor fuel composition containing: (I) the reaction product of maleic anhydride, a polyether polyamine, and a hydrocarbyl polyamine; and (II) at least one polyolefin polymer, copolymer, or corresponding hydrogenated polymer or copolymer of a C.sub.2 -C.sub.6 hydrocarbon, said polymer/copolymer having an average molecular weight in the range of 500-3500, and to a motor fuel additive concentrate containing said reaction product and polymer/copolymer components.
Incomplete combustion of a hydrocarbonaceous motor fuel in an internal combustion engine is a common problem which generally results in the formation and accumulation of carbon deposits on various parts of the combustion chamber as well as on the fuel intake and exhaust systems of the engine. The presence of carbon deposits in the combustion chamber seriously reduces the operating efficiency of the engine. First, deposit accumulation within the combustion chamber inhibits heat transfer between the chamber and the engine cooling system. This leads to higher temperatures within the combustion chamber, resulting in increases in the end gas temperature of the incoming charge. Consequently, end gas auto-ignition occurs, which causes engine knock. In addition, the accumulation of carbon deposits within the combustion chamber reduces the volume of the combustion zone, causing a higher then design compression ratio in the engine. This, in turn, also results in serious engine knocking. A knocking engine does not effectively utilize the energy of combustion. Moreover, a prolonged period of engine knocking will cause stress fatigue and wear in vital parts of the engine.
The above-described phenomenon is characteristic of gasoline powered internal combustion engines. It is usually overcome by employing a higher octane gasoline for powering the engine, and hence has become known as the engine octane requirement increase (ORI) phenomenon. It would be highly advantageous if engine ORI could be substantially reduced or eliminated by preventing carbon deposits in the combustion chamber of the engine.
Another problem relates to the accumulation of carbon deposits in the carburetor which tend to restrict the flow of air through the carburetor at idle and at low speeds, resulting in an overrich fuel mixture. This condition also promotes incomplete fuel combustion and leads to rough engine idling and engine stalling. Excessive hydrocarbon and carbon monoxide exhaust emissions are also produced under these conditions. It would be desirable from the standpoint of engine operability and overall air quality to provide a motor fuel composition which minimizes or overcomes the above-described problems.
2. Information Disclosure Statement
Co-assigned U.S. Appl. Ser. No. 821,727, filed on Jan. 23, 1986 (incorporated herein by reference) discloses the use of the reaction product of maleic anhydride, a polyether polyamine, and a hydrocarbyl polyamine in a gasoline motor fuel to reduce engine ORI and provide carburetor detergency;
U.S. Pat. No. 4,357,148 discloses the use of the combination of an oil-soluble aliphatic polyamine component containing at least one olefinic polymer chain and having a molecular weight range of 600-10,000, and a polymeric component which may be a polymer, copolymer, hydrogenated polymer or copolymer, or mixtures thereof having a molecular weight range of 500-1500 to reduce or inhibit ORI in motor fuels;
U.S. Pat. No. 4,191,537 discloses the use of a hydrocarbyl poly(oxyalkylene) aminocarbonate, having a molecular weight range of 600-10,000 and also having at least one basic nitrogen atom per aminocarbonate molecule, to reduce and control ORI in motor fuels;
Co-assigned U.S. Pat. No. 3,502,451 discloses the use of C.sub.2 -C.sub.6 polyolefin polymers or hydrogenated polymers having a molecular weight range of 500-3500 in motor fuels to eliminate or reduce deposition on the intake valves and ports of an internal combustion engine;
U.S. Pat. No. 3,438,757 discloses the use of branched chain aliphatic hydrocarbyl amines and polyamines having molecular weights in the range 425-10,000 to provide detergency and dispersancy in motor fuels; and
Co-assigned Rep. of South Africa Appl. No. 731911, filed on March 19, 1973, discloses a motor fuel composition comprising a polymeric component which is a polymer or copolymer of a C.sub.2 -C.sub.6 unsaturated hydrocarbon having a molecular weight in the range 500-3500, and a hydrocarbyl-substituted amine or polyamine component, said motor fuel composition having effectiveness in reducing engine intake valve and port deposits.